<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<html>
<head>
<!-- Copyright 1997 The Open Group, All Rights Reserved -->
<title>&lt;float.h&gt;</title>
</head><body bgcolor=white>
<center>
<font size=2>
The Single UNIX &reg; Specification, Version 2<br>
Copyright &copy; 1997 The Open Group

</font></center><hr size=2 noshade>
<h4><a name = "tag_000_005_095">&nbsp;</a>NAME</h4><blockquote>
float.h - floating types
</blockquote><h4><a name = "tag_000_005_096">&nbsp;</a>SYNOPSIS</h4><blockquote>
<pre><code>

#include &lt;float.h&gt;
</code>
</pre>
</blockquote><h4><a name = "tag_000_005_097">&nbsp;</a>DESCRIPTION</h4><blockquote>
The characteristics of floating types are defined in terms of a
model that describes a representation of floating-point numbers
and values that provide information about an
implementation's floating-point arithmetic.
<p>
The following parameters are used to define the model for each
floating-point type:
<img src="../images/floath1.gif" border=0>
<p>
FLT_RADIX will be a constant expression suitable for use in the <b>#if</b>
preprocessing directives.  All except FLT_RADIX and FLT_ROUNDS have separate
names for all three floating-point types.  The floating-point model
representation is provided for all macro names except FLT_ROUNDS.
<p>
The rounding mode for floating-point addition is characterised by
the value of FLT_ROUNDS:
<dl compact>

<dt>-1<dd>indeterminable

<dt>0<dd>toward 0.0

<dt>1<dd>to nearest

<dt>2<dd>toward positive infinity

<dt>3<dd>toward negative infinity

</dl>
<p>
All other values for FLT_ROUNDS characterise implementation-dependent
rounding behaviour.
<p>
The macro names given in the following list will be defined as
expressions with values that are equal or greater
in magnitude (absolute value) to those shown, with the same
sign.
<p>
<img src="../images/floath2.gif" border=0>
<p>
The macro names given in the following list will be
defined as expressions with values that will be
equal to or greater than those shown.
<br>
<img src="../images/floath3.gif" border=0>
<p>
The macro names given in the following list will be
defined as expressions with values that will be
equal to or less than those shown.
<p>
<img src="../images/floath4.gif" border=0>
<br>
</blockquote><h4><a name = "tag_000_005_098">&nbsp;</a>APPLICATION USAGE</h4><blockquote>
None.
</blockquote><h4><a name = "tag_000_005_099">&nbsp;</a>FUTURE DIRECTIONS</h4><blockquote>
None.
</blockquote><h4><a name = "tag_000_005_100">&nbsp;</a>SEE ALSO</h4><blockquote>
None.
</blockquote><hr size=2 noshade>
<center><font size=2>
UNIX &reg; is a registered Trademark of The Open Group.<br>
Copyright &copy; 1997 The Open Group
<br> [ <a href="../index.html">Main Index</a> | <a href="../xshix.html">XSH</a> | <a href="../xcuix.html">XCU</a> | <a href="../xbdix.html">XBD</a> | <a href="../cursesix.html">XCURSES</a> | <a href="../xnsix.html">XNS</a> ]

</font></center><hr size=2 noshade>
</body></html>
